Hollow Metal Microneedles

Hollow Metal Microneedles Array of hollow metal microneedles. The needles taper from a tip diameter of 75 micrometers to a base diameter of 300 micrometers over their 500 micrometer length. The wall thickness is ten micrometers. A conventional 27-gauge needle is shown for comparison. An array of tiny metal needles can draw blood for glucose monitoring or other diagnostic tests with less pain than a conventional needle (shown in foreground for comparison.) This research was supported in part by National Science Foundation grant BES 98-13321. (Date of Image: April 2002)